Back in 1989 two marine invertebrate biologists were discussing the subject of new species when the both went ‘whoa’ realizing that they’d independently discovered the same creature 1,000 miles apart. One scientist found them in Morro Bay, California while the other scientist discovered them on urchins on Vancouver Island in British Colombia.

Living on the finer spines which rest closer to the body of sea urchins, the Waldo Arthuri, is a small (0.2 inches long) clam-like creature that travels around like a snail. Because the little guys are so fragile it’s been hard for the researchers to really analyze them although they’ve been able to extract DNA which has led them to declare this a new species that’s not documented yet.

Why these things live on urchins is still an unknown.

“What they get out of the relationship is pretty mysterious. The urchin might provide shelter to the clam, and there might be food flowing in the water to the urchin that the clam might be able to filter out and benefit from. What the clam gives to its host, if anything, is pretty unknown.”